Use Async process and enable to watch status on stats
Add command of changing CONNECTION_POOL_EXPTIME & DEFAULT_LOST_ACTION & CONNECTION_DESCRIPTOR_TABLE_SIZE & WRITEBEHIND_SHIFT_SIZE
Revert "add new function "calculate latency average""

This reverts commit 4158ccdf1e01774854f0f463fd90c20ac8ba58ba.

Conflicts:
	ruby/server/lib/roma/command/sys_command_receiver.rb
	ruby/server/lib/roma/event/handler.rb